Electrical problem

Tiny
SILVERSPINNER
  • MEMBER
  • 1999 CHRYSLER 300
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 102,000 MILES
1999 Chrysler 300M. My car would not start, so I jumped it and took it in for repair. Mechanic said my battery must have a loose plate and replaced the battery. Nothing changed. Mechanic reports battery voltage in car (engine not running) tests 12 volts sometimes, and tests 7.5 volts next time. Almost no resistance on cables. Suggestions?
Monday, January 17th, 2011 AT 2:09 AM

3 Replies

Tiny
SILVERSPINNER
  • MEMBER
  • 2 POSTS
Problem solved. Car home.
Was this
answer
helpful?
Yes
No
-1
Monday, January 17th, 2011 AT 5:35 PM
Tiny
CARADIODOC
  • MECHANIC
  • 34,330 POSTS
The secret is where that 7.5 volts is being measured. Is it on the battery posts or on the cables that are attached to those posts? The secret is to start right on the posts, then move each voltmeter probe, one at a time, to the next place down the line to see where the voltage drops. This only works when current is being drawn from the battery. This test is normally done while trying to crank the engine, but in your case it might also work just by turning on the head lights.

Also, don't overlook the connections where the smaller red positive cable is bolted to the under-hood fuse box.

Caradiodoc
Was this
answer
helpful?
Yes
No
Tuesday, January 18th, 2011 AT 4:32 PM
Tiny
CARADIODOC
  • MECHANIC
  • 34,330 POSTS
What was the solution?
Was this
answer
helpful?
Yes
No
Tuesday, January 18th, 2011 AT 4:33 PM

Please login or register to post a reply.

Related Engine Not Running Content

Car Cranking but Not Starting? Try This
VIDEO
Car Cranking but Not Starting? Try This
Instructional repair video
Engine Not Starting
GUIDE
Engine Not Starting
Over the past 20 years at 2CarPros we have identified the top problems that are easily fixed. This guide can save you a trip to the repair garage or calling a tow truck and...
VIEW MORE